Attachment for sewing machines



Dec. 8, 1936. v J, D. KARLE ATTACHMENT FOR SEWING MACHINES Filed July20, 1955 2 Sheets-Sheetl I6? ,33 10.1? l e4 2z Z117 14 M ,l l v g5` 1' lI T) I' 15 ,2a "I I l I] lf .l0 l1 12 :ji/,y )ccpl -u" 3 WIW d/ y Qq] 30,es 1 I 3E LVJ/m E1n/UW John D. Karla @mj/Z1 Dec. 8, 1936. J. D. KARLEATTACHMENT FOR SEWING MACHINES Filed July 20, 1935 2 Sheets-Sheet 2 maWilli/[0212i I gmc/Whom floh/n D. Karla Patented Dec. 8, 1936 UNITEDSTATES PATENT OFFICE ATTACHMENT FOR SEWING MACHINES Application July 20,

8 Claims.

This invention relates to sewing machines and more particularly to apresser-foot which is vibrated laterally of the line of seam and isadapted to be used for making ornamental seams.

The several features of the present invention will be clearly understoodfrom the following description and accompanying drawings in which:-

Figure 1 is a front elevation of a zigzag-stitching attachment with myimproved presser-foot attached, showing the needle in raised positionand the position of the presser-foot at the completion of the right toleft shifting movement.

Figure 2 is an elevation similar to Figure 1 showing the position of thepresser-foot after the left to right shifting movement has beencompleted.

Figure 3 is a top plan view of the presserfoot.

Figure 4 is a bottom plan view of the presserfoot.

Figure 5 is a sectional view taken substantially along the line 5 5 ofFigure 3.

Figure 6 is a side elevation of the stitch-linger, and Figure 7 is a topplan View of the finished work showing the seam produced by theattachment.

This invention is shown applied to a zigzagstitching attachmentcomprising a plate Ill xed to the presser-bar of the machine and formedwith a cross-arm II which slidably carries a bar I2 having a dependingportion I3. Pivotally secured by the pivot-pin I4 to the plate I0 is alever I5 which is actuated by the needle-clamp I6 carried by the usualreciprocatory needle-bar I1 journaled in the head of the machine andcarrying a needle I1.

The lever I5 carries a spring-pressed pawl I8 which actuates aratchet-wheel I9 pivoted on the plate I0 and having rigidly attached toits rear face a cam 2@ the circumferentially spaced projections of whichengage the inwardly extending projections 2I formed on the member 22which is fulcrumed on the pivot-pin 23. Pivotally secured by the screw24 to the upstanding post 25 of the cross-arm II is a bell-crank lever26 one arm of which is bifurcated to receive the stud 21 carried by theswingable member 22 and the other arm formed with an arcuate slot 28. Alink 29 operatively connects the slidable bar I2 to the bell-crank lever26 and has one of its ends secured by the pivot-pin 3D to the bar I2 andits other end adjustably secured to the bell-crank lever by thethumb-screw 3I which extends through the arcuate slot 28. The abovedescribed 1935, Serial No. 32,349

mechanism for vibrating the presser-foot laterally of the line of seamformation is shown in my co-pending application Serial No. 758,381, ledon December 20, 1934, to which reference may be had for a more detaileddisclosure.

My improved presser-foot comprises a shank 32 which is adapted to beremovably secured to the depending portion I3 of the slidable bar I2 bythe screw 33. The shank 32 carries a rectangular shaped sole-portion 34which is formed with a needle-opening 35 and a Work-engaging surface.The lower face of the sole-plate in rear of the needle-opening is cutaway to provide a clearance groove 31 for the thread-loops and thesole-plate in front of the needle-opening 35 is formed with a half-roundgroove 3B which leads to the needle-opening to provide clearance for theinitial stitches of the raised ornamental seam On the upward movement ofthe needle-bar I1 the needle-clamp I6 engages the free end of the leverI5 and moves the lever I5 and pawl I8 upwardly. During its upwardmovement the pawl I8 engages the ratchet-wheel I9 and advances it andthe cam one-eighth of a revolution. The rotation of the cam 20 causesone of its circumferentially spaced projections to contact one of theinwardly extending projections 2| on the swinging member thereby causingthe member to swing in a clockwise direction about its pivot 23. Thisswinging movement causes the pin 21 to swing the bell-crank lever in acounterclockwise direction about its pivot and this movement is impartedto the Slide-bar I2 by means of the link 29 thereby causing thepresser-foot to move to the left to the position shown in Figure 1. Theshifting of the presser-foot occurs while the usual feed-dog 44 is belowthe throatplate 45 and is completed just prior to the point in the cyclewhen the feed-dog contacts the work. After the feed-dog has advanced thework, the needle descends forming the stitch on the right side of thestitch-iinger, (Fig. 1), and on the upstroke of the needle theneedle-clamp I6 again engages the free end of the lever I5 and the pawlagain advances the ratchet-wheel and cam 20. The movement of the camcauses the swingable member 22 to shift in a counter-clockwise directionabout its pivot and this movement is transmitted to the bar l2 by thebell-crank-lever 26 and the link 29, thereby shifting the presser-footto the right to the position shown in Figure 2. The needle then descendson the left side of the stitch-finger forming a stitch and theneedlethread extends from the rst needle-hole across the stitch-:lingerto the second needle-hole. From the foregoing it will be observed thatthe zigzag attachment acts to shift the presser-foot laterally of theline of seam formation so that the needle descends rst on one side ofthe stitch-finger and then on the other. The tension on the thread iscomparatively tight and as the stitches are formed over thestitch-iinger the stitches which have been laid over the finger causethe work to move with the presser-foot whereby the work is shiftedlaterally relative to the needle. The stitches 45 are formed near thetop of the downwardly inclined thread-deecting portion 4| of thestitch-linger and when the stitch is being set the tension on theneedle-thread causes the thread overlying the stitch-finger to slidedown the downwardly inclined portion of the stitchnger so that thethread will be moved in rear of the needle-path to prevent its beingpierced by the needle during the succeeding stitch-forming cycle.

Upon continued operation of the machine a series of stitches 46, (Fig.'7), are formed in the work 4l and over the stitch-inger and thesestitches are fed forward by the feed-dog until they ride off of thetapered tongue of the stitchnger thereby forming a raised ornamentalseam on the material being stitched.

It will be obvious that the stitch-finger may be removed by looseningthe screw 40 and a stitchfinger of a different width placed on thepresserfoot in order that seams of different widths may be produced. Itis to be understood that the screw 3l may be adjusted in the slot 28 tovary the lateral throw of the presser-foot in accordance with the widthof the stitch-iinger.

Having thus set forth the nature of the invention, what I claim hereinis:-

1. A presser-foot for sewing machines comprising a shank, a sole-platecarried thereby, and a stitch-iinger carried by said sole-plate, saidstitchfinger having an abruptly downwardly inclined thread-delectingportion.

2. A presser-foot for sewing machines comprising a shank, a sole-plateformed with a needle-opening and carried by said shank, and astitch-linger secured to the upper face of said sole-plate, saidstitch-finger having an abruptly downwardly inclined thread-deflectingportion extending through said needle-opening and a horizontallydisposed rearwardly extending tongue.

3. A presser-foot for sewing machines comprising a shank, a sole-portioncarried by said shank, said sole-portion being formed with aneedle-opening, an unobstructed groove extending from the toe of saidsole-portion to said needle-opening and a second groove extending fromsaid needle-opening to the heel of said sole-portion, a stitch-fingercarried by said sole-portion and extending into said needle-opening andthrough said second mentioned groove and means for adjustably anddetachably securing said stitch-nger to said sole-portion.

4. A presser-foot for sewing machines comprising a shank, a sole-portioncarried by said shank and formed with a needle-opening, a grooveextending from the toe of said sole-portion to said needle-opening, anda clearance notch in rear of said needle-opening, and a stitch-fingeradjustably secured to said sole-portion and having a downwardly inclinedportion located in said needle-opening and a rearwardly extending tongueentering the clearance notch in rear of said needle-opening.

5. In combination with a sewing machine having a needle-bar adapted tobe reciprocated in a xed path, a thread-carrying needle secured to saidneedle-bar, a presser-foot, a stitch-nger carried by said presser-footand formed with a downwardly inclined and rearwardly extendingthread-deilecting portion, and means actuated by said needle-bar forvibrating said presser-foot laterally relative to the needle, wherebythe needle descends on rst one side and then the other side of saidstitch-finger and the needle-thread is laid across said stitch-finger.

6. In combination with a reciprocatory needle and work-feedingmechanism, a laterally vibratory presser-foot, and a stitch-fingercarried by said presser-foot and formed alongside the path of the needlewith a downwardly inclined threaddeflecting portion.

7. In combination with a reciprocatory needle and work-feedingmechanism, a stitch-finger having an abruptly downwardly inclinedportion located adjacent said needle and means for laterally vibratingsaid stitch-finger and needle relative to each other.

8. In combination with a reciprocatory needle and work-feedingmechanism, a stitch-finger having horizontally disposed portions locatedat different elevations and connected by an abruptly downwardly inclinedportion located adjacent said needle and means for laterally vibratingsaid stitch-finger and needle relative to each other.

JOHN D. KARLE.

